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Journal of Advanced Dielectrics 2011年第4期1卷 455-464页

作者： k.sambasiva rao HAILEEYESUS WORkINEH A.SWATHI B.S.kALYANI Department of Physics Andhra University Visakhapatnam 530003India

Polycrystalline(Bi_(0.94)Na_(0.94))_(0.5)Ba_(0.06)TiO_(3)ceramics(r=0,0.04,and 0.08,designated as BNBT6:BNBT6:4Dy and BNBT6.8Dy,respectively)were prepared by conventional high tem-perat ure sintering *** X-ray difraction patterms show pure perovskite structure with no secondary *** parameters and unit cell volumes have decreased due to Dy_(2)O_(3)*** micrographs revealed denser samples(prel>97%)with wmiformly distributed *** room temperature piezoelectric properties of Dy_(2)O_(3)substit ut ed sample at a=0.04 wererelatively higher.d_(33)=147 pC/N,k_(p)=28%and Q_(m)=-*** samples exhibited infinitesimalchange in thickness(α15 nm)to an applied voltage of 100 V,which could be utilized in *** behavior and broad dielectric maxima with diffuse phase transition wereobser *** value of RT dielectric constant has increased while dielectric loss was decreased dueto Dy_(2)O_(3),*** in the materials obeys Jonscher's universal power *** conductivity in the low frequency region is associated with short range translational hopping whileit is associated with the reorientational hopping in the high frequency *** charge carrier concentration term remained constant over the entire temperature range of(30-500°C).

关键词： X-ray diffraction relaxor ferroelectrics dielectric properties piezoelectric properties conductivity

e-FILTERS OF MS-ALGEBRAS

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Acta Mathematica Scientia 2013年第3期33卷 738-746页

作者： M. sambasiva rao Department of Mathematics M.V.G.R. College of EngineeringChintalavalasa Vizianagaram Andhra Pradesh India-535005

The notion of e-filters is introduced in an MS-algebra and characterized. The concept of D-filters is introduced and a set of equivalent conditions under which every D-filter is an e-filter are given. The properties of the space of all prime e-filters of an MS-algebra are observed. The concept of D-prime filters is introduced and then a set of equivalent conditions axe derived for a prime e-filter to become a D-prime filter in topological terms.

关键词： MS-algebra e-filter dense element D-filter D-prime filter minimal prime filter Hausdorff space

Friction stir surfacing of cast A356 aluminiumesilicon alloy with boron carbide and molybdenum disulphide powders

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Defence Technology（防务技术） 2015年第2期11卷 140-146页

作者： R.SRINIVASU A.sambasiva rao G.MADHUSUDHAN REDDY k.SRINIVASA rao Department of Metallurgical Engineering Andhra University Defence Metallurgical Research Laboratory

Good castability and high strength properties of Ale Si alloys are useful in defence applications like torpedoes,manufacture of Missile bodies,and parts of automobile such as engine cylinders and *** wear resistance of the alloys is major limitation for their *** stir processing(FSP) is a recognized surfacing technique as it overcomes the problems of fusion route surface modification *** in view of the requirement of improving wear resistance of cast aluminiumesilicon alloy,friction stir processing was attempted for surface modification with boron carbide(B4C) and molybdenum disulfide(Mo S2) ***,micro compositional analysis,hardness and pin-on-disc wear testing were used for characterizing the surface composite *** study revealed breaking of coarse silicon needles and uniformly distributed carbides in the A356 alloy matrix after *** and uniformity in hardness was obtained in surface composite *** wear resistance was achieved in friction stir processed coating with carbide *** of solid lubricant Mo S2 powder was found to improve wear resistance of the base metal significantly.

关键词： A356合金二硫化钼堆焊技术硅合金钼粉末碳化硼摩擦铸铝

Impact of communication time delays on combined LFC and AVR of a multi-area hybrid system with IPFC-RFBs coordinated control strategy

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Protection and Control of Modern Power Systems 2021年第1期6卷 89-108页

作者： C H.Naga Sai kalyan G.sambasiva rao EEE Department Acharya Nagarjuna UniversityGunturA.P.India EEE Department RVR&JC College of EngineeringGunturA.P.India

In this paper,the impact of communication time delays(CTDs)on combined load frequency control(LFC)and automatic voltage regulation(AVR)of a multi-area system with hybrid generation units is *** reveals that CTDs have significant effect on system performance.A classical PID controller is employed as a secondary regulator and its parametric gains are optimized with a differential evolution-artificial electric field algorithm(DE-AEFA).The superior performance of the presented algorithm is established by comparing with various optimization algorithms reported in the *** investigation is further extended to integration of redox flow batteries(RFBs)and interline power flow controller(IPFC)with *** reveals that IPFC and RFBs coordinated control enhances system dynamic ***,the robustness of the proposed control methodology is validated by sensitivity analysis during wide variations of system parameters and load.

关键词： Combined LFC-AVR Communication time delays(CTDs) IPFC-RFBs strategy DE-AEFA algorithm

Electron Paramagnetic Resonance and Optical Absorption Studies on Copper Ions in Mixed Alkali Cadmium Phosphate Glasses

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Journal of Materials Science & Technology 2009年第4期25卷 531-534页

作者： G. Giridhar M. Rangacharyulu R.V.S.S.N. Ravikumar P. sambasiva rao Department of Physics Acharya Nagarjuna University Department of Chemistry Pondicherry University

Electron paramagnetic resonance （EPR） and optical absorption studies were carried out at room temperature on copper doped mixed alkali cadmium phosphate （LiNaCdP） glasses to understand the nature and symmetry of dopant. Three samples with varying concentrations of alkali ions have been prepared. The spin Harniltonian parameters obtained from room temperature EPR spectra are： gli=2.437, 9⊥=2.096, A‖=117×10-4 cm-1, A⊥=26×10-4 cm-1 for LiNaCdP1, g‖=2.441, g⊥=2.088, A‖=121×10-4 cm-1, A⊥=25×10-4 cm-1 for LiNaCdP2and g‖=2.433,g⊥=2.096, A‖=125×10 4cm-1, A⊥=32×10-4cm-1 for LiNaCdP3. TheseEPR results indicate that the dopant Cu2＋ ion enters the glass matrix into a tetragonally elongated octahedral site. The bonding parameters evaluated by correlating optical and EPR data suggest that bonding between the central metal ion and ligands is partially covalent. The mixed alkali effect in cadmium phosphate glasses was reported.

关键词： Glasses Electron paramagnetic resonance (EPR) Optical properties

Evaluation of in-vitro antibacterial activity and anti-inflammatory activity for different extracts of Rauvolfia tetraphylla *** bark

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Asian Pacific Journal of Tropical Biomedicine 2012年第10期2卷 818-821页

作者： B.Ganga rao P.Umamaheswara rao E.sambasiva rao T.Mallikarjuna rao V.S.Praneeth.D A.U College of Pharmaceutical Sciences Andhra UniversityVisakhapatnamA.P

Objective:To assess the in-vitro antihacterial activity and anti-inflammatory activity of orally administered different extracts(Hydro-alcoholic,methanolic,ethyl acetate and hexane)of Rauvolfia tetraphylla(***)root bark in Carrageetiaii induced acute inflammation in ***:In-vitro antibacterial activity was evaluated for extracts against four Gram positive and four Gram negative bacteria by using cylinder plate ***-alcoholic extract(70%v/v ethanol)at 200,400 and 800 mg/kg doses and methanolic,ethyl acetate and hexane extracts at doses 100,200 and 400 mg/kg were tested for anti-inflammatory activity in Carrageenan induced rat paw oedema model and paw thickness was measured every one hour up to 6 ***:All extracts of *** root bark showed good zone of inhibition against tested bacterial *** Carrageenan induced inflammation model,hydro-alcoholic and methanolic extract of *** root bark at three different doses produced significant(Pk shows good in-vitro antibacterial activity and in-vivo anti-inflammatory activity in rats.

关键词： Rauvolfia tetraphylla Root bark In-vitro antibacterial activity Inflammation Anti-inflammatory activity

Improved Routing Protocol for Health Care Communications

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Open Journal of Applied Biosensor 2013年第2期2卷 51-56页

作者： Jayanthi k. Murthy V. sambasiva rao Department of Electronics and Communication B.M.S College of Engineering Bengaluru India Department of Electronics and Communication P.E.S Institute of Technology Bengaluru India

Wireless Body Area Network (WBAN) technology has significantly increased the potential of remote healthcare monitoring systems. The devices used for WBAN have limited energy resources. For most devices it is impossible to recharge or change the batteries. Since the data mostly consists of medical information, high reliability and low delay is required. The main objective of this simulation study is to evaluate the performance of routing protocol on static IEEE 802.15.4 to determine the most suitable routing protocol for Wireless Body Area Networks. Here, investigations on the various routing protocol suggest cluster topology and AODV as the probable candidate. About 16% improvement in the energy consumption was observed when modifications were made considering the energy and mobility, thus achieving high residual battery capacity and eliminating the need for recharging the batteries.

关键词： Wireless Body Area Network ZigBee Networks Routing Protocol

Copper interactions with DNA of chromatin and its role in neurodegenerative disorders

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Journal of Pharmaceutical Analysis 2013年第5期3卷 354-359页

作者： M.Govindaraju H.S.Shekar S.B.Sateesha P.Vasudeva Raju k.R.sambasiva rao k.S.J.rao A.J.Rajamma Molecular Biophysics Unit Indian Institute of Science Department of Pharmacy Practice KIMS Hospital and Research CenterVIPS Department of Pharmaceutics Acharya & B.M.Reddy College of Pharmacy Department of Neuroscience Medical University of South Carolina Department of Biotechnology Acharya Nagarjuna University Centre for Neuroscience Institute for Scientifc Research and Technological services INDICASAT-AIP Department of Pharmacognosy KLEU's College of Pharmacy

In this study, we have demonstrated the conformational changes to DNA induced by abnormal interactions of copper using circular dichroism, in combination with UV-absorbance and fluorescence spectroscopy. Results confirm that binding of copper to bases of DNA in chromatin is concentration dependent. Binding efficiency of Cu2~ ions to DNA is increased in proportion to the degree of unwinding of the double helix induced by denaturation. Altered B-DNA conformation will alter the integrity of DNA which may affect the normal process of DNA replication and transcription. Copper induced DNA damage in the brain may cause neurotoxicity and the neuronal cell death and is implicated in Alzheimer＇s disease and other neurological disorders.

关键词： Human brain Chromatin DNA Copper Neurodegenerative disorders

Pore water trace metal chemistry in polluted sediments of a tropical estuary of SE Brazil

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Chinese Journal Of Geochemistry 2006年第B8期25卷 66-67页

作者： sambasiva rao Patchineelam Edouard Metzger Didier J uel Gerard Sarazin Departamento de Geoquimica Universidade Federal Fluminense Niteroi Brazil Laboratoire de Geochimie des Eaux University Paris 7 France

Effect of Ba2+ in BNT ceramics on dielectric and conductivity properties

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Natural Science 2010年第4期2卷 357-367页

作者： konapala sambasiva rao kuan China Varada Rajulu Bollepalli Tilak Anem Swathi 不详

The polycrystalline (Na0.5Bi0.5)1-xBaxTiO3 (x = 0.026, 0.055 & 0.065) (BNBT) ceramics have been synthesized by conventional solid state sinter-ing technique. The tolerance (t) factor of the BNBT composition have been estimated and found to be 0.988, 0.990 and 0.991 for x = 0.026, 0.055 and 0.065 respectively, revealing system is stable perovskite type structure. The com-pound has a rhombohedral-tetragonal Morphtropic Phase Boun- dary (MPB) at x = 0.065. XRD re-sults indicated the crystalline structure of the investigated materials are of single phase with rhombohedral structure and the average parti-cle size of the calcined powder is found to lie between 45 nm - 60 nm. The effect of Ba2+ on dielectric and conductivity properties in Bis-muth Sodium Titanate (BNT) has been studied. The variation of dielectric constant with fre-quency (45 Hz-5 MHz) and temperature (35℃-590℃) has been performed. The value of Tm and Td are found to decrease with increase of concentration of Barium in BNT. The value of tan in the studied materials is found to be the order of 10-2 indicating low loss materials. The evaluated Curie constant in the composi-tion is found to be the order of 105 revealing the materials belong to oxygen octahedra ferro-electrics. The theoretical dielectric data of the studied composition have been fitted by us- ing Jonscher’s dielectric dispersion relation: . The pre-factor a(T), which indicates the strength of the po-larizability showed a maximum at transition temperature (Tm). The exponent n(T) which gives a large extent of interaction between the charge carriers and polarization is found to be minimum in the vicinity of Tm. The A.C. and d.c conductivity activation energies have been eva- luated;the difference in activation energies could be due to the grain boundary effect. The activation enthalpy energies, have been esti-mated and found to be Hm = 0.37 eV, 0.26 eV and 0.25 eV for BNBT-26, BNBT-55 and BNBT-65 re-spectively.

关键词： MPB Dielectric Perovskite Conductivity Tolerance Factor